limerock production and demand B

ProsPects for southeast Lee county

limerock production and demand B

Introduction

Limerock Mining in the DR/GR Area

Estimates of Permitted Limerock Reserves

Discussion of Future Aggregate Demand

Reserve Estimates Compared to Future Demands

Conclusion on Aggregate Demand

Uncertainties

Notes

B.2

B.3

B.5

B.10

B.13

B.15

B.16

B.17

B.2 Ju l y 2008


Lee County has a majority of the commercially valuable limerock deposits in southwest Florida. These deposits are mined as raw material for building products such as concrete, asphalt, and concrete block.

The amount of additional limerock already approved for mining in Lee County has never been estimated, making it difficult for county officials to determine if more DR/GR land needs to be converted to limerock mining. Until now, the best data available has been the “expected life of the mine” information in Florida Department of Environmental Protection (FDEP) permit files. These estimates are self-reported by mining applicants and range from 10 to 25 years for Lee County’s active mines and 42 years for a mine expansion that has not begun operation due to federal permitting issues.

The overall absence of statewide data on rock reserves was a major concern of the Strategic Aggregates Review Task Force. One of its consensus recommendations (in February 2008)1 was for the state to provide an estimate of the rock volume available from already permitted mines in order to compare it to projected demand. Such an analysis is provided here for mines in Lee County’s DR/GR area.

Knowledge of permitted reserves is essential to future DR/GR planning. Limerock products are an important resource to the local and regional economy and the best deposits are somewhat limited in geographic area. Reserving sufficient land for mining is critical to the economy, yet avoiding over-allocation is also critical because mining is an industrial process that unavoidably destroys natural resources and is not compatible with most other uses of nearby land. In addition to permanent removal of all vegetation, limerock mining physically removes significant portions of the porous rock that stores and protects groundwater that flows into Lee County’s potable water wellfields.

Mining companies generally consider information on their rock quality and reserves to be proprietary business information. Florida’s most recent report on mining, the Strategic Aggregates Study,2 claimed that data on

introduction

rock reserves was available only for a few properties across the entire state that had revealed their reserves through public documents.3 That study apparently based its conclusions about mining reserves in Lee County on a 2001 News-Press article about a zoning hearing,4 reaching the following conclusion about the future of mining in Lee County:

The Rinker mega-mine complex in Lee County produces at least 5 million tons of construction aggregates each year for growth and development, maintenance and repairs in Southwest Florida. The Rinker mine complex will exhaust reserves by 2015. New mines to replace the mega-mine capacities of this facility will be difficult, if not impossible to permit in this area. When the mine reserves are gone, aggregates will be imported at greater expense.5

This conclusion completely misrepresents Lee County’s mining reserves. It was given prominent attention in the Strategic Aggregates Study and was relied on by Florida legislators to justify attempts to preempt local governments from regulating mining throughout the entire state.

This appendix includes an analysis of limerock resources in the DR/GR area that have already been permitted for removal or could be permitted for removal if current applications are approved. Future demand for limerock is then assessed, allowing a comparison to reserves that have been already permitted for removal and rezoning requests for additional mines.

Ju l y 2008 B.3

L imerock Production and demand in southwest fLorida

Limerock is the common name for products made from naturally occur-ring limestone. In Lee County, most of the commercially valuable lime-stone comes from the Ochopee geological unit, which is the most pro-ductive shallow aquifer and the primary aquifer tapped for public water supply in Lee County at this time.6

Limerock is relatively soft compared to some types of rock but is plentiful in several parts of Florida. Hauling costs make up such a large proportion of the cost to purchasers of fill dirt and rock products that local sources are a great economic advantage where products must be hauled by truck.

A few products, such as the top layer of asphalt paving known as the “friction course,” are more durable when made with extremely hard rock. For instance, the friction course on I-75 generally uses crushed granite from quarries in Georgia, Alabama, and Canada. The Strategic Aggregates Study concluded that the Rinker mine complex was the only quarry in Lee County that produced crushed stone for roadbuilding,7 but although no mines in Lee County produce friction course aggregate, they do produce crushed stone products that meet numerous FDOT quality standards.

FDOT sets standards for rock quality but does not monitor which mines have certain materials for sale at any given time. When improving state roads, FDOT contractors can purchase stone products from any FDOT-certified supplier who can meet the specifications for a particular project, regardless of the original source of the products.

Limerock products from mines in the DR/GR area are primarily crushed stone, and include the following types:

Rip-rap – large pieces of stone that are used to protect embankments and shorelines from erosion.Base rock – partially crushed limestone that includes a uniform mix of small and large pieces (up to 3½” in diameter). Base rock is later compacted in place to provide the support for asphalt paving.Graded aggregate – course pieces of crushed limestone that have been washed and then sorted according to size. This becomes a major component of concrete and asphalt.Sand – Some mines in Lee County wash and sort very small pieces of crushed stone which is then sold as screenings, fine aggregates, or

•

•

•

•

limerock mining in the dr/gr AreA

manufactured sand. Sometimes this material is instead discarded by backfilling it into quarry pits, especially the smallest particles. Florida DOT has not certified any Lee County mines to produce the kind of natural sand that is mixed with cement and crushed stone to make concrete; that type of sand is currently being mined in Glades County. Aggregates – This is a broad term that can include all of the other products listed above.

No mines in southwest Florida produce blocks of stone that can be used whole for construction purposes.

Limerock deposits in southwest Florida are not limited to Lee County; southern Charlotte County has limerock that is mined commercially. Collier County has several limerock mines in operation and others have recently been approved at locations shown on Figure B-1.

About half of the limerock produced in Florida comes from the Lake Belt which is located at the northwestern edge of Miami-Dade County’s urban area, about 135 miles from Fort Myers. The Lake Belt is linked to a major

•

Rock is extracted from a mining pit in the right side of the above image; aggregate process-ing is taking place in the upper right corner of the image.

B.4 Ju l y 2008


rail network, allowing those mines to economically supply aggregate to distant markets including Orlando and Jackson-ville. Although Lee County is much closer to the Lake Belt than Orlando or Jacksonville, the absence of a convenient rail link to southwest Florida keeps Lake Belt aggregate from being avail-able locally at competitive prices.

Figure B-1 shows major sources for limerock products in south Florida. These include large limerock mines, aggregate terminals at ports where rock products arrive by ship, and rail terminals where limerock products arrive by rail from the Lake Belt. Major sources are surrounded by rings with a radius of 25 and 50 miles. Most deliveries from mines or terminals are less than 30 miles, but some deliveries from regional mines can be as long as 80 to 100 miles one way with no back-haul opportunities.9

In April 2008 Palm Beach County approved 11,000 more acres (about 75 years’ worth) of limerock mining in the Everglades agricultural area just south of Lake Okeechobee, in addition to the 4,000 acres approved two years earlier. These mine sites are about 80 miles by road from Fort Myers, too distant to replace DR/GR mines but within economical trucking distance of some Hendry County and Glades destinations.

Lee County’s flat topography requires extensive use of fill mate-rial to elevate roads, parking lots, and buildings. For new devel-opments, fill material is usually produced on-site by excavating stormwater detention areas, often beyond minimum require-ments. Fill obtained in this manner (which may also contain some limerock) typically cannot be sold to others due to county regulations that define off-site sale as commercial mining.

Demand for fill material that cannot be obtained on-site is pur-chased from commercial “borrow pits” or from limerock mines whose operators must remove what they consider “overburden” that lies over more commercially valuable limerock. This analy-sis does not attempt to quantify fill material that is excavated specifically for resale or that is available commercially as over-burden from limerock mines.

Figure B-1: Major sources for limerock products in South Florida, as identified in public records of Lee and Collier Counties; web sites of individual suppliers; FDOT databases of approved aggregate sources; and Strategic Aggregates Study (FDOT, March 2007)

Legend

Limerock Mines

Aggregate Terminals at Ports

Rail Terminals

25 Mile Radius

50 Mile Radius

Ju l y 2008 B.5


A previous analysis of limerock reserves in the DR-GR area was performed for Lee County by Greg F. Rawl, P.G. That analysis sought to determine the potential amount of limestone that could be mined from the DR/GR area in the future. Rawl estimated that 160 million cubic yards of limerock had been excavated in Lee County through 2001 and that 1,800 million more cubic yards were available in the DR/GR area alone,10 even after excluding potential preservation areas. The resource itself is sufficiently plentiful in Lee County that the existence of lime-rock alone should not be a justification for approval of mining if surface or environmental conditions would make it unwise.

The new analysis described here begins with a more specific focus: to determine the amount of limerock that has already been permitted for removal or may be permitted for removal if additional approvals are obtained.

This analysis is based on data in the public record, primarily Lee County zoning and development order files, but in some cases permit files of the Department of Environmental Protection (for most commercial mines) and the South Florida Water Management District (for excavations that received permits as early phases of residential develop-ments). Where these files did not provide sufficient data (e.g, the average depth to the top of productive limerock deposits or the average thickness of limer-ock), estimates were taken from Rawl.11

This analysis includes the entire Rinker mine com-plex that straddles the DR/GR boundary just north of Florida Gulf Coast University. It also includes the Bonita Grande Aggregates mine that was annexed into the city of Bonita Springs DR/GR area in 2003;

estimAtes of permitted limerock reserves

Table B-1: Mines in southeast Lee County; approved, partially-approved, and applications in process or litigation.

Legend

Limerock Mines

Aggregate Terminals at Ports

Rail Terminals

25 Mile Radius

50 Mile Radius

Project Mine AcresMine nAMe forMer nAMe or LocAtion sec-twP-rge Acres

Approved MinesRinker Materials (s. of Alico) Florida Rock Ph. 1-A (northerly) 11, 12-46-25 915 537

Rinker Materials (n. of Alico) Florida Rock Ph. 3-A, 3-B 5, 6-46-26 1,194 622

Rinker Materials (Ginn Lago) Florida Rock Ph. 1-B, 2-A, 2-B 7, 8, 17, 18, 19, 20-46-26 3,560 1,357

Florida Rock (Miromar Lakes) Florida Rock Ph. 1-A (southerly) 13, 14-46-25

Florida Rock Greenmeadows Harper Bros. Green Meadows 35-45-26; 2, 3-46-26 1,521 1,075

Florida Rock Greenmeadows exp. SE expansion of Green Meadows 1, 11, 12-46-26 1,529 1,132

Youngquist Brothers West Lakes; University Lakes 9, 10, 11, 15, 16, 21-46-26 1,955 1,511

Cemex/RMC Corkscrew Woods (s. of Corkscrew) 28-46-26 309 228

Westwind Corkscrew (n. of Corkscrew; far east) 22, 23-46-27 603 299

Bell Road (replaces Sunstate; s. of 82) 27, 34-45-27 504 265

Bonita Grande Aggregates Bonita Farms I & II 17, 20-47-26 1,321 557

Bonita Land Resources Highgate Corp. 33-47-26 48 32

Plumosa Farm Sanfilco 33-47-26 37 30

TOTALS: 13,496 7,645

Partially-Approved MinesFlorida Rock Mine #2 (IPD vacated; no ACOE permit) 26, 27, 28, 33, 34, 35,

36-45-27;28, 31, 32, 33-45-27

4,839 2,471

Mine Applications that are Pending or in LitigationCorkscrew Excavation (n. of Corkscrew) 19-46-27; 23, 24-46-26 1,366 840

Golfrock (n. of Corkscrew) 22-46-27 253 142

Estero Group (n. of Corkscrew) 23-46-27 318 251

Schwab 640 Corkscrew Lakes 30-47-26 644 378

Schwab II (also s. of Corkscrew) 29-46-27 600 318

Cypress Bay (s. of Corkscrew) 27, 33, 34-46-27 953 267

Ibis Lake Estates (s. of SR 82) 34-45-27 93 61

TOTALS: 4,227 2,257

B.6 Ju l y 2008


Figure B-2: Limerock permitted for removal (or may be permitted depending on additional approvals)

Legend

Approved mines

Partially approved mines

Applications in process or litigation

Ju l y 2008 B.7


Mine AcresApproved1980-2006

Mine AcresDug

1980-2006

Details of Acres Dug, 1980-2006:

Acres of Rock Exca-vated1980- 2000

Avg. RockThick-ness

C.Y. of Rock Excavated1980-2006

Tons of Rock Ex-cavated

1.35 tons / C.Y.

RemainingLimerock

Acres

C.Y. of Rock To Be Excavated2007-Futurefill-

only pits

open rock pits

refilled rock pits

Rinker Materials (s of Alico) 537 537 0 336 201 537 23 19,926,280 26,900,478 0 0

Rinker Materials (n. of Alico) 622 189 0 189 0 189 17 5,183,640 6,997,914 433 11,875,747

Rinker Materials (Ginn Lago) 1,357 1,209 0 1,209 0 1,209 23 44,861,960 60,563,646 149 5,528,893

Florida Rock (Miromar Lakes) 191 0 191 0 191 25 7,703,667 10,399,950 0 0

Florida Rock Greenmeadows 1,075 765 0 679 86 765 25 30,855,000 41,654,250 310 12,503,333

Florida Rock Greenmeadows exp.

1,132 184 0 184 0 184 25 7,421,333 10,018,800 948 38,236,000

Youngquist Brothers 1,511 554 350 204 0 204 30 9,873,600 13,329,360 1,307 63,258,800

Cemex/RMC 228 181 0 181 0 181 30 8,760,400 11,826,540 9 435,600

Westwind Corkscrew 299 240 240 --- --- --- --- --- --- ---

Bell Road 265 6 6 --- --- --- --- --- --- ---

Bonita Grande Aggregates 557 430 293 137 0 137 30 6,630,800 8,951,580 420 20,328,000

Bonita Land Resources 32 26 26 --- --- --- --- --- --- ---

Plumosa Farm 30 8 8 --- --- --- --- --- --- ---

TOTALS: 7,645 4,520 923 3,310 287 3,597 141,216,680 190,642,518 3,576 152,166,373

an annexation agreement stipulates that this mine must cease operations after 2018, but mining can continue under its county approval until then.For purposes of this analysis, each mine has been assigned to one of three groups: approved; partially approved; or application in process or in litigation. Mines are listed by their current names or owners even though their approval documents often reflect names of prior owners. Boundar-ies of existing and proposed mines are shown on Figure B-2; summary information for each mine is provided in Table B-1.

Figure B-3 shows mines that have already been approved. The geographic extent of limerock mining through 2006 is shown in light blue and the approved limits of mining are shown in medium blue. Mines that are ap-proved to remove fill-dirt only are shown in dark blue. Two mines have light blue outlines that identify the original edges of mining pits that have since been backfilled with unsalable material. A portion of two mines are

outlined in black to indicate the edges of shallow lakes from prior fill dirt operations on those sites that will be re-excavated to recover limerock.Acreages from Figure B-3 are tabulated in Table B-2. Table B-2 also contains estimates of limerock volume in cubic yards of material removed from the ground. The actual volume of limerock extracted depends on many factors, most importantly the thickness of the mineral deposit and the permitted excavation depth. The finished volume also varies by the type of product; for instance, rip-rap has more space between stones while fine aggregates have less.

Reliable date on limerock thickness is sometimes available in public records. For instance, when renewing mining permits, each mine must now submit to Lee County a survey of the area and depth of mine pits. The pits are assumed for this analysis to have been excavated to the bottom of the limestone layer; the “average depth” of limestone reported in Table B-2 is based on these

Table B-2: Capacity of mines already approved

B.8 Ju l y 2008


Figure B-3: Mines already approved

Legend

Geographic extent of limerock mining through 2006

Approved limits of mining

Mines approved to remove fill-dirt only

Original edges of mining pits backfilled with unsalable material

Edges of shallow lakes from prior fill dirt operations

Ju l y 2008 B.9


surveys when they are available. In some cases, soil borings are also in public records indicating the elevation of the top of the limestone layer. In other cases, both the top and bottom of the limestone layer has been esti-mated from soil borings or from regional geological data.12 The accuracy of this analysis will be improved if mine operators are willing to provide additional data in their possession that can improve these estimates of limerock thickness.

Limerock volumes are sometimes expressed in either “short tons” or metric tons. Table B-2 converts cubic yards to “short tons” to allow comparisons with other statewide data sources. Each short ton equals .9072 metric tons.

Additional permitted mining acreages for each mine are also included in Table B-2, along with an estimated quantity of limerock yet to be mined, using the methodology just described.

Figure B-4 shows proposed mines now in the application process. For each, the proposed mining tract is outlined and the size of the proposed mining pit is indicated by solid color. Most are currently at some stage in Lee County’s application process and are shown in red. One of these mine sites (Schwab 640) had been approved in 1989 for fill-dirt mining and a subsequent residential development; that approval has lapsed. A later request to mine that entire site for limerock was denied by the County Commission in 2002 and is the subject of ongoing litigation.

One mine, shown in yellow, is indicated as “partially approved.” This extremely large mine is proposed by Florida Rock with an expected lifespan of 56 years.13 IPD zoning, along with a site and phasing plan, was approved by the County Commission in 1993. State environmental permits were issued in 2000. Federal dredge-and-fill permits could not be obtained due to potential impacts on the Florida panther; Florida Rock later agreed to maintain a wildlife corridor through the mine and received their federal permits in 2003. A judge revoked those permits in 2004, rul-ing that the cumulative impacts on the Florida panther from this mine and nearby development activity had not been considered by federal agencies. Later in 2004, Lee County determined that the site plan approved in 1993 had been “vacated” because further county approvals had not obtained with specified time periods. Florida Rock is now in the federal permitting process and presumably will ask Lee County to reinstate the site plan if federal permits can be obtained.

Figure B-4: Proposed mines now in the application process

Legend

Mines in application process or litigation

Partially approved mine

B.10 Ju l y 2008


discussion of future AggregAte demAnd

Limerock products are essential building materials in Florida. A thick layer of compacted limerock supports every asphalt road and parking lot. Asphalt and concrete are both made with large quantities of crushed stone, as is concrete block and pipe. Although out-of-state substitutes are available, locally-produced limerock products have strong economic ad-vantages. Additional recycling of asphalt and concrete is highly desirable but will never fully replace mining of new limerock.

National trends have shown an increasing reliance on crushed stone to replace naturally occurring sources of gravel. Crushed stone consumption has also been increasing as new homes become larger, new roads are built to serve spread-out development patterns, and infrastructure built in prior generations needs to be replaced.

The recent building boom overtaxed every segment of the construction industry. Even plentiful products like limerock skyrocketed in price, due mainly to limited processing facilities rather than any shortage of raw material. These price increases triggered major investments for additional mining capacity in Lee County at the same time that major corporate entities worldwide have been consolidating their ownership. Even though new residential construction is nearly at a standstill in Lee County, mine investors expect it to resume at some point and intend to be ready to compete to supply whatever demands emerge.

The potential effect of litigation over mining in Miami-Dade County’s Lake Belt has also fueled the recent influx of mining proposals in Lee County. Another factor fueling the recent influx of mining proposals in Lee County is the potential effects of litigation over mining in the Miami-Dade County Lake Belt. Although this decision has been overturned, a federal judge had ruled in July 2007 that environmental regulators failed to properly protect the county’s public water supply. The judge temporarily shut down mining in a portion of the Lake Belt with the greatest potential to contam-inate Miami-Dade County’s wellfields. This decision affected 20%-30% of the Lake Belt according to various reports, forcing production to move to other approved areas of the Lake Belt that were not affected by the ruling. The construction downturn was already in full motion at the time so it

is unlikely that there have been any direct impacts on Florida’s economy or other limerock suppliers. However, that could change if construction reverts to boom levels before the public water supply issues have been resolved.

Most aggregate data is published only at the national or regional level, but Florida-specific data has been located for the years 1976 through 2006.14 Figure B-5 shows annual production in Florida of “crushed stone” (aggregates made from limerock) and “construction sand and gravel” (from natural sources).

Also shown on Figure B-5 is Florida’s population during that same period. The amount of aggregate produced annually in Florida has increased at about the same rate as Florida’s permanent population. This relationship has caused a number of industry observers to express future aggregate de-mand at the current annual consumption rate, which for Florida is about 9 tons per permanent resident.15

Large stockpiles of aggregate have accumulated since the building downturn in 2007.

Ju l y 2008 B.11


Housing starts, florida Poupulation, and construction Aggregatessold or Used in florida, 1976--2007

0

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Popu

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Housing Starts (in number of dwelling units)

All Aggregates Sold or Used (crushed stone plus sand & gravel)

Crushed Stone, in thousands of short tons

Construction Sand & Gravel, in thousands of short tons

Florida Population

Figure B-5

Housing starts, florida Poupulation, and construction Aggregatessold or Used in florida, 1976--2007

0

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Housing Starts (in number of dwelling units)

All Aggregates Sold or Used (crushed stone plus sand & gravel)

Crushed Stone, in thousands of short tons

Construction Sand & Gravel, in thousands of short tons

Florida Population

B.12 Ju l y 2008


This ratio between aggregate production and permanent population may not hold in future years. It disregards the impact of part-time Florida residents, who are not counted in the permanent population but who are responsible for a significant share of the building and road construc-tion that consumes aggregates. When this method is scaled down to the county level, it is even more unreliable because the precise service area for regional mines such as those in the DR/GR area is not known.

Other indicators of aggregate demand have been rising at rates similar to Florida’s permanent population, as shown in Figure B-6. The average size of new houses and the mileage of roads have risen at slightly lower rates than the population since 1975, while the number of miles traveled by all vehicles has risen at a slightly higher rate. The increasing rate of travel is an indicator of prosperity, low oil prices, and spread-out development pat-terns, thus creating a demand for additional road construction.

A better way to assess future demand for construction aggregates would tie demand more closely to expected growth instead of cumulative per-manent population. Florida comprehensive plans already are based on accommodating expected growth; each plan must be based on growth

forecasts that can also be used to evaluate potential demand for aggre-gates.

These estimates are generally based on population projections created by the Bureau of Economic and Business Research (BEBR) at the University of Florida. Because these forecasts are for the permanent population only, they are commonly adjusted with recent census data to reflect the peak season population in order to be useful in forecasting peak demand for public facilities. The same adjustments are needed to accurately forecast demand for limerock.

To evaluate this methodology, the number of housing starts in Florida has been obtained back to 1976.16 Housing starts are tracked carefully be-cause building permit statistics include buildings that are never construct-ed. The number of housing starts each year is also shown on Figure B-5.

It is clear from Figure B-5 that an increase in the number of housing starts causes an immediate increase in aggregate production; however, this impact is not proportional to the number of housing starts. Aggregates are also used in commercial construction, which often lags but occasion-ally leads residential construction; and aggregates are needed in large quantities for infrastructure, which may lag the residential development it supports by many years. These and other uses for aggregates smooth out the annual demand for aggregates; yet in the longer run the demand is probably more closely related to the number of housing starts than to the cumulative number of permanent residents. Any useful methodology should allow a direct comparison to the acre-age needed for future mining in Lee County (initially by assuming that the amount of the regional market served by Lee County mines would stay the same in future years). If this regional market assumption should change for any reason, such as new mines outside Lee County, or a new rail line that can transport aggregate, or the availability of alternate ma-terials that could replace aggregate, then these forecasts can be adjusted accordingly.

The following analyses apply to each methodology separately.

florida Population from 1975 through 2007-- compared to other indicators of aggregate demand --

0

5 ,0 0 0 ,0 0 0

1 0 ,0 0 0 ,0 0 0

1 5 ,0 0 0 ,0 0 0

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F lorida perm anent populat ionF lorida c enterline-m iles of public roads (FDO T)U.S . average s iz e of new hous es in s quare feet (US Cens us )F lorida annual vehic le m iles of t ravel in m illions (FDO T)

1,655

2,248

64,492

203,783

98,984121,995

Figure B-6

Ju l y 2008 B.13


reserve estimAtes compAred to future demAnd

One basic way to assess demand for limerock products is to assume continuing an-nual consumption at today’s rate of nine tons per permanent resident. This method was used by Rawl to compute expected demand for limerock for Lee County’s population through 2030.17 The total projected demand through 2030 for each county in southwest Florida is computed in Tables B-3 and B-4 using this approach.

Table B-3 assumes the permanent population for each county will match the medium population projections from BEBR.18 These projections have been broken down into five-year incre-ments, with the average annual aggregate demand for each county during each increment shown in the first five columns of Table B-4 (based on nine tons per person per year). The sum of the annual demands for 2007 through 2030 are provided in the sixth column.

If each county had suitable mineral reserves and produced its own aggregate, these totals could be used to determine the amount of land that would be needed for mining in each county. Although Collier County has substantial reserves, nearby coun-ties to the east and north have only minor reserves or none at all. A look at the recent past provides some guidance as to what percentage of the demand from these seven counties might be supplied by Lee County mines in the future.

There is no data that assesses what percentage of their lime-rock demand is met from sources other than mines in Collier, Lee, and Charlotte Counties such as aggregate terminals at Port Manatee or the Port of Tampa or the mines near Brooksville (see Figure B-1).

REGIONAL POPuLATION

CountyEstimated

2005Projected

2010 2015 2020 2025 2030CHARLOTTE 154,030 175,400 192,800 208,600 222,700 235,900

COLLIER 317,788 379,200 440,100 497,500 549,200 598,500

DESOTO 32,606 35,700 39,900 42,600 45,100 47,300

GLADES 10,729 11,600 12,100 12,600 13,000 13,400

HENDRY 38,376 41,400 44,600 47,600 50,400 52,900

LEE 549,442 676,500 782,600 881,700 970,700 1,053,900

SARASOTA 367,867 413,000 451,400 486,500 517,400 545,700

TOTALS: 1,470,838 1,732,800 1,963,500 2,177,100 2,368,500 2,547,600

TOTAL PROjECTED LIMEROCk DEMAND BASED ON PER CAPITA RATE

CountyAnnual demand Demand in tons

2007-2030Demand in tons at 80%

2007-2030Demand in CY at 80%

2007-20302007-2010 2011-2015 2016-2020 2021-2025 2026-2030CHARLOTTE 1,482,435 1,656,900 1,806,300 1,940,850 2,063,700 43,268,490 34,614,792 25,640,587

COLLIER 3,136,446 3,686,850 4,219,200 4,710,150 5,164,650 101,450,034 81,160,027 60,118,539

DESOTO 307,377 340,200 371,250 394,650 415,800 8,839,008 7,071,206 5,237,931

GLADES 100,481 106,650 111,150 115,200 118,800 2,660,922 2,128,738 1,576,843

HENDRY 358,992 387,000 414,900 441,000 464,850 9,974,718 7,979,774 5,910,944

LEE 5,516,739 6,565,950 7,489,350 8,335,800 9,110,700 179,575,956 143,660,765 106,415,381

SARASOTA 3,513,902 3,889,800 4,220,550 4,517,550 4,783,950 101,114,856 80,891,885 59,919,915

TOTALS: 14,416,371 16,633,350 18,632,700 20,455,200 22,122,450 446,883,984 357,507,187 264,820,139

Table B-3: Projected population increase in Southwest Florida (“Projections of Florida Population by County, 2006-2030,” Bureau of Economic and Business Research, University of Florida, Febru-ary 2007)

Table B-4: Total projected limerock demand for Southwest Florida’s population through 2030 using a per capita rate (see text for explanation)

B.14 Ju l y 2008


However, the percentage of the regional demand for limerock can be inferred from following methodology. Table B-2 estimates that the total limerock production from DR/GR mines since 1980 has been 141,216,680 cubic yards, which equates to 190,642,518 tons (based on 1.35 tons per cubic yard). This material was mined over approximately a 26-year period, yielding an average annual tonnage of 7,332,405. At the average Florida rate of nine tons per person per year, this tonnage would serve a permanent population of about 812,000, which is about 80% of the aver-age population for these counties during the same period (1,014,809).

The final two columns in Table B-4 adjust the future demand for all seven counties by this 80% factor to estimate the amount of limerock that may be needed from DR/GR mines based on this methodology, expressed in tons and in cubic yards. For the entire region, this total is 174% of the amount of aggregate produced by DR/GR mines from 1980 through 2006 (as computed in Table B-2).

An alternative method of assessing future demand for construction aggre-gates would reflect the peak-season population and expected growth rates rather than cumulative permanent population.Table B-5 summarizes the results of this method for each county in southwest Florida. It compares the total number of dwelling units built from 1980 through 2006 to the number expected to be built from 2007 through 2030, to help estimate whether more or less limerock might be needed during this next planning period.

This method begins by adjusting census data and population forecasts to reflect the total number of dwelling units built during each period (rather than just the number of dwelling units occupied by permanent residents). Source information is available variously from BEBR and the American Community Survey (part of the U.S. Census Bureau). For the rural coun-ties, some extrapolation from 2000 U.S. Census data was required.

Based on this analysis for the entire region, Table B-5 estimates that 105% of the amount of aggregate produced by DR/GR mines from 1980 through 2006 will be needed to accommodate growth from 2007 through 2030. This method understates the likely need for limerock mining by

PEAk-SEASON POPuLATION AND ExPECTED GROwTh RATES

Total Dus 2006 Percent of Dus household Total Dus Total Dus Dus Built 2030 Add’t Pop. Add’t Dus % increase

County in 1980 Population Occupied, 2000 Size, 2000 in 2006 in 2006 1980-2006 Population 2007-2030 2007-2030 over ’80-’06CHARLOTTE 34,798 160,315 80.1% 2.18 96,060 61,262 235,900 75,585 43,286 71%

COLLIER 50,743 326,658 71.2% 2.39 187,615 136,872 598,500 271,842 159,749 117%

DESOTO 7,458 33,164 79.0% 2.70 15,548 8,090 47,300 14,136 6,627 82%

GLADES 3,475 10,796 66.5% 2.51 6,468 2,993 13,400 2,604 1,560 52%

HENDRY 7,032 38,678 88.3% 3.09 14,176 7,144 52,900 14,222 5,212 73%

LEE 111,013 585,608 76.9% 2.31 341,117 230,104 1,053,900 468,292 263,620 115%

SARASOTA 113,355 379,386 82.2% 2.13 216,926 103,571 545,700 166,314 94,990 92%

TOTALS: 327,874 1,534,605 36,192 841,718 550,036 2,547,600 1,012,995 575,045 105%source: Census BEBR Census Census Amer.Comm.Survey BEBR

Table 5: Peak-season population and expected growth rates in Southwest Florida

Ju l y 2008 B.15


basing demand on expected growth, disregarding the demand that the ex-isting population would create as existing homes and infrastructure need to be rebuilt. The first method has the opposite problem, overstating the likely need for limerock mining by disregarding the impacts of growth on the demand for aggregates.

No actual data is available to determine the portion of aggregate produc-tion that is attributable to new growth versus routine rebuilding. This study assigns a subjective factor of 3/4 to the growth factor and 1/4 to the rebuilding factor, resulting in an assumed need for 2007 through 2030 of 122% of the aggregate production from 1980 through 2006.

The amount of aggregate that can be produced from an acre of land depends on the quality and consistency of the limestone and the thickness of its layer. Assuming that future mining in the DR/GR encounters condi-tions that are similar to the mining of 3,597 acres from 1980 through 2006, the 122% increase suggests that 4,397 acres would need to be mined from 2007 through 2030. This equals about 183 acres per year av-eraged over this entire planning period — in total, about 22% more land than has already been permitted by Lee County.

This figure of 4,397 acres has a contingency factor because, as shown in Table B-2, much of the land already permitted has a thicker layer of lime-stone than land that was mined through 2006. Limestone thickness can be taken into account directly by taking the amount mined through 2006 (141,216,680 cubic yards) and applying the 122% factor for the planning period from 2007 through 2030. This results in an expected demand of 172,284,350 cubic yards, about 13% more than Table B-2 suggests can be removed from land that already is permitted for mining.

These methodologies can be extended beyond 2030 but with decreasing reliability. Current population projections for 2030 did not assume that Florida’s recent hypergrowth would continue indefinitely but they did not anticipate anything like the extended period of very low growth that is now being experienced. Also, reliance on the ratio of nine tons per per-manent resident per year becomes increasingly problematic as Florida’s population continues to increase, for the reasons discussed earlier in addi-tion to the generally slowing rate of growth expected in southwest Florida through 2030 and beyond.

Special caution must be attached to attempts to forecast regional growth through 2060 based on numbers in two recent statewide planning stud-ies.19 20 BEBR’s official projections for the future population of counties end at the year 2030. To reach the year 2060, these reports made the as-sumption that statewide growth from 2030 to 2060 would be at the same rate as growth from 2005 through 2030. For the hypothetical statewide purposes of those particular studies, that assumption was acceptable. However, extending that assumption to coastal counties where most of the developable land is already occupied would lead to extremely unreal-istic growth scenarios.

conclusion on AggregAte demAnd

Two methods of projecting future demand for aggregate were presented in this appendix. The first method assumes that aggregate demand will remain at its current rate of 9 tons per year per permanent resident and that total annual demand will rise proportionately with the number of permanent residents. The second method assumes the aggregate demand will be more closely related to growth than to cumulative permanent population.

Both methods are complicated by two essential facts:• Lee County mines are a primary supplier of aggregate products for much of southwest Florida. • The thickness of the limestone layer and the quality of aggregate that can be produced vary from site to site across the DR/GR area.

The forecast recommended by this study relies more heavily on the sec-ond method (growth) than the first (cumulative population). A subjective factor of 3/4 has been assigned to the growth factor and 1/4 to the cu-mulative population factor. The resulting forecast is that 4,397 additional will need to be mined from 2007 through 2030. This equals about 183 acres per year averaged over this planning period — in total, about 22% more land than the 3,576 acres that have already been permitted by Lee County.

B.16 Ju l y 2008


uncertAinties

Many factors would cause these estimates of limerock reserves to vary. Reliance on these estimates must be tempered by awareness that they can be affected by factors that can be anticipated but not predicted. Here are some such factors:

factors that could shorten or lengthen the predicted reserves:Actual growth rates in southwest Florida could be considerably faster or slower than the official state projections.If an adequate rail line were built to serve Lee County and DR/GR mines, aggregate could be shipped much further at competitive costs. A rail line to Florida ports or the Miami-Dade County Lake Belt could import products that would reduce production in DR/GR mines, but it could also open up DR/GR mines to a larger market than is now pos-sible, depleting reserve capacity more quickly.

factors that could increase pressure on dr/gr mines, thus using up reserves more quickly:

If the temporary restrictions on Lake Belt mining near Miami-Dade County’s wellfields become permanent or expand to a larger area, increased pressure could be felt on DR/GR mines even though, for the most part, the Lake Belt mines serve a different market. If Charlotte County were to prohibit limerock mining, its demand would be met almost entirely by DR/GR mines. If Collier County were to prohibit mining, its demand would be met by a combination of DR/GR mines and mines in the Lake Belt and the Everglades Agricul-tural Area.

factors that could decrease pressure on dr/gr mines, thus prolong-ing reserves:

The state legislature may preempt local control of mining. Although Lee County applies stringent standards to all mines, the county has never tried to stop mining and in fact continues to be the regional supplier for aggregate. The direct effect of preemption would have little, if any, effect on the amount of limerock mined in Lee County. However, preemption could shift more mining to Collier County or to environmentally sensitive areas further east in the DR/GR area, or could re-start mining in Lee County’s urban areas, which would also reduce demands on existing DR/GR mines.

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Growth in southwest Florida may never recover to the rates that had been forecast in recent years. The state’s rapidly increasing cost of living, its property tax treatment of newcomers, and rising insurance costs could permanently slow the migration of new residents, thus decreasing pressure on DR/GR mines.Alternate sources for construction aggregates could reach the market. If these products were durable and cost-effective, pressure on DR/GR mines would be decreased.New mines could be opened within or outside Lee County. As recently as 1990, the Florida Geological Survey (FGS) believed that commer-cially usable limestone didn’t exist as far south and east in the DR/GR as is now known to be the case (the blue area in Figure B-7 indicates areas where FGS believed limestone would be economically feasible to mine).21 Further subsurface explorations throughout southwest Florida may identify more land that could be mined for limerock.Current plans to improve the aggregate-handling capacity of Florida ports could be accelerated. Without an active rail connection to Lee County, this capacity probably would not directly serve Lee County, but it could reduce demand from DR/GR mines in the outer portions of their service area.

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Figure B-7: Solid blue indicates areas believed to be economically feasible to mine limerock according to the Florida Geological Survey’s analysis in 1990

Ju l y 2008 B.17


notes

1. Strategic Aggregates Review Task Force Final Report, February 1, 2008, page 15, published on-line at: www.dot.state.fl.us/statematerialsof-fice/administration/resources/library/issues-trends/aggtaskforce/meet-ingfour/finalreport.pdf – accessed May 5, 2008.

2. Strategic Aggregates Study: Sources, Constraints, and Economic Value of Limestone and Sand in Florida, March 12, 2007, published on-line at: www.dot.state.fl.us/statematerialsoffice/administration/resources/li-brary/issues-trends/documents/aggregatestudy.pdf – accessed May 5, 2008.

3. Strategic Aggregates Study, part II, page 22.

4. Strategic Aggregates Study, part II, page 22.

5. Strategic Aggregates Study, part I, page 38.

6. Lee County Groundwater Resource and Mining Study, Greg F. Rawl, P.G. and Michael Voorhees, P.E., page 82 (June 2005 draft).


8. Official test data indicates that aggregate from the Rinker mine is slightly harder, denser, and less absorbent than crushed stone from other Lee County mines, all qualities that improve its performance in asphalt (personal communication from John Shoucair, FDOT Geotechnical Mate-rials Engineer, March 28, 2008).


10. Lee County Groundwater Resource and Mining Study, chapter VIII, section E.

11. Lee County Groundwater Resource and Mining Study, appendix IV.

12. Lee County Groundwater Resource and Mining Study, appendix IV.

13. Testimony of Russell Schropp to Lee County Hearing Examiner, Janu-ary 14, 2005, case ADM-2004-00011.

14. Historic data compiled by Construction Market Research, 508 Edge-wood Road, Pittsburgh, PA 15221.

15. Lee County Groundwater Resource and Mining Study, pages 96-97.

16. Annual State and County Building Permits and Housing Starts in Florida, 1976-2007, Bureau of Economic and Business Research, War-rington College of Business, University of Florida, 2008.

17. Lee County Groundwater Resource and Mining Study, page 95–99.

18. Projections of Florida Population by County, 2006-2030, Florida Population Studies Volume 40, Bulletin 147, Bureau of Economic and Business Research, Warrington College of Business, University of Florida, February 2007.

19. Florida 2060: A Population Distribution Scenario for the State of Florida, prepared for 1000 Friends of Florida by the GeoPlan Center at the University of Florida, August 15, 2006

20. An Alternative Future: Florida in the 21st Century 2020 2040 2060, prepared for the Metropolitan Center for Regional Studies at the Univer-sity of Central Florida by the City Planning 702 Urban Design Studio at the University of Pennsylvania.

21. Mineral Resources of Lee County, Florida, Florida Geologic Survey Map Series No. 130, 1990 (with current DR/GR boundary superimposed).

Documents

limerock production and demand B